


Healthy Unhealthy Relationship

by tenser



Category: Durarara!!
Genre: BDSM, Established Relationship, M/M, Sex Toys, Smut, Teaching A Lesson, Violation of Intimacy
Language: English
Status: Completed
Published: 2016-07-14
Updated: 2016-07-14
Packaged: 2018-07-23 22:28:33
Rating: Explicit
Warnings: Rape/Non-Con
Chapters: 1
Words: 3,415
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/7482378
Author URL: https://archiveofourown.org/users/tenser/pseuds/tenser
Summary: <blockquote class="userstuff">
              <p>Shizuo and Izaya have managed to form a relationship that works for them, and lately they've rarely broken from having kinky sex to leave the house. </p><p>It's a relationship that's easy to misunderstand from the outside, and Kasuka, for one, wants to punish Izaya for sexually torturing his brother by giving the shifty information broker a taste of his own methods.</p>
            </blockquote>





	Healthy Unhealthy Relationship

**Author's Note:**

> Originally written as "From the Outside" in response to this prompt on the kink meme:  
> http://drrrkink.livejournal.com/2346.html?thread=7256618#t7256618
> 
> "My request is Shizaya, formed relationship, both live together, and Shizuo hardly goes outside anymore due to extremely kinky-kinky time with Izaya all the time. 
> 
> Kasuka of course is worried and goes over to check on his brother, believing Izaya is tricking him into everything, and discovers them in the middle of perhaps a drug fetish game with Shizuo all drugged up.
> 
> Anyway, Kasuka freaks out and knocks out Izaya and "rescues" Shizuo, with the intent of raping Izaya with a ton of different kinky toys they have as revenge for "defiling" his older brother. =3"

They stopped needing the blindfold hours ago. 

Shizuo can barely see through the drug-induced haze. The edges of Izaya’s couch closest to his vantage point on the floor are more firm than fuzzy, but otherwise, the details of the information dealer’s apartment blur like the unimportant backdrop they are. 

The only thing that matters is the pleasure Izaya gives him. 

His dark-haired lover is murmuring sweet things in his ear. The flea’s mouth never stops running and it never stops irritating Shizuo. Even though they’ve hammered out the better part of the jagged edges between them, there are still rough spots that cause irritation. Those edges soften and blur in the haze of sex, or drugs or both, just like his unfocused eyesight at the moment.

“Shizu-chan~”

Izaya’s hot breath in his ear pumps a pulse of thick arousal into his cock. Whatever shit the flea gave him this time hasn’t interfered with his ability to get an erection. His cock’s been ridden already and the sloppy patch of come on his abdomen is proof of Izaya’s pleasure as well as his own. 

“Is my monster hard again?” Izaya snickers, reaching down to play with the head of Shizuo’s interested cock. He presses his small naked body against his lover, resting his head in the crook of Shizuo’s neck. 

Shizuo tries to grunt, but he can’t even speak. They didn’t use a ball gag this time, but the drugs retard his tongue.

“You’re so amusing like this, Shizu-chan,” Izaya whispers twisted words of endearment into his ear. He hates how they make his cock stiffen every time despite the annoyance. “All mine, to do whatever I want with.”

“Just try to stop me,” Izaya commands, his lips curling into a smile and then a biting kiss that digs into his neck. “Try.”

Strain as he might, Shizuo cannot escape the simple ropes binding his slowly-numbing arms. The drugs make him incapable of violence; they _fix_ him. He can’t hurt Izaya when he’s like this. 

“Try harder, you monster,” Izaya’s voice gets mean and Shizuo’s rage sparks. But his body can't move.

“Don’t you want to tear me apart, Shizu-chan?” Izaya goads. “I want you to try to rip me to shreds. You’re so glorious like that, Shizu-chan. Like a real monster.”

What Izaya says is cruel, but his hands speak the language of pleasure as they slide over his engorged cock. 

Shizuo knows Izaya loves his violence, if only for the thrill it gives the twisted information broker. The flea wouldn’t have irritated him for years otherwise. What exactly his lover gets out of these drug sessions where his violence is surpressed he isn’t sure and doesn’t really want to know. That Shizuo gets peace out of them is enough.

Izaya’s nimble fingers continue to flicker over his cock; other fingers massage the delicate skin between his balls and hole. The other man is playing with him, setting his body on fire, and Shizuo only grows harder through the expert touch. 

“Yes, drool, Shizu-chan,” Izaya smiles wildly as he licks the wet spittle. “Like a racehorse straining. My animal.”

“My precious pet,” Izaya whispers directly in his ear as the smaller man mounts Shizuo’s larger frame. Their cocks are flush, and Shizuo hopes that maybe they’ll get off grinding against each other. The times when Izaya rides him, his face is too distant and mocking, no matter how beautifully he eventually comes undone. Shizuo likes it better when the arrogant flea is down on his level, the floor itself. 

Izaya grinds their cocks together, then teases Shizuo’s cock between his thighs. The head pops up between his buttcheeks, rubbing at the small hole it so often sinks into. But Izaya isn’t interested in that just yet, he’s more interested in giving Shizuo just the promise of intimate connection while lavishing his bitter praises and leaving lovemarks across Shizuo’s chest. 

The blond drinks in sensations as his lover slowly loses himself in the erotic friction. Shizuo may not be able to move much or see well, but he can feel. Every centimeter of Izaya’s skin burns against him, despite the lube and come lubricating the slide of their bodies. Strands of Izaya’s sweaty hair stick to Shizuo’s chest as the smaller man’s crimson eyes meet his own. 

Their lips meet, an explosion of passion and need, though Shizuo is more recipient than participant. 

“So big,” Izaya licks his lips, reaching back to nudge Shizuo’s cock against his entrance. Shizuo frowns; Izaya says that every time. “I’m tight again Shizu-chan, you have to fuck me open.”

Shizuo whimpers as Izaya grins and positions his hips to take the cock—

—suddenly the door flies open. 

***

Kasuka is initially surprised that the code his brother gave him actually worked on Orihara’s door, but the scene before him quickly draws all his attention. 

His older brother is bound with ropes and stark naked on the floor. Perched above him in a very compromising position is an equally naked Orihara Izaya. Shizuo looks like he’s been bound for some time—there are purple welts forming near the ropes. More worrisome is the unfocused look in his eyes and the complete slackness of his body. 

Kasuka loses it. 

He may not be strong like his brother, but it doesn’t take much power in his punch to send an unprepared Orihara reeling from a punch to the jaw. The crumpled body collapses against a nearby chair.

As Kasuka unties his brother, he fumes at the way the information broker treated his precious sibling. It sickens him to see his wonderful brother humiliated. 

At first, Kasuka had nodded with understanding when Shizuo said he’d put aside his differences with “the flea” and they’d starting seeing each other. But he didn’t like or trust Orihara, and had always suspected blackmail or manipulation. The big brother he knew would never submit to a snake like Orihara willingly.

He only wanted his brother’s happiness. So he didn’t say anything.

When Shizuo slowly started disappearing from the streets of Ikebukuro after hours, he didn’t comment. When he stopped returning Kasuka’s calls and texts, he didn’t complain. But when Tom called him and said Shizuo had quit his job and hadn’t been seen in weeks, Kasuka decided to investigate. 

He drags his limp brother unto the couch. For all Shizuo’s strength, he’s light. He looks like he might have passed out. Kasuka gets a container of milk and places it on the table; gets out his phone and calls a car.

A knifepoint digs into his throat from behind.

“Oh Kasuka, my dear brother-in-law to be, you should put down that phone,” Izaya is all steel.

Kasuka puts it down and turns to face the naked information dealer. The man’s face lights up in a smile.

“Shizu-chan and I are just showing our affection,” Izaya grins. “Though it may look a little incomprehensible to those on the outside.”

Kasuka shakes his head. A little of the rage his brother feels, he thinks it might exist in him too. 

“Now step aside and let me get my clothes, and then we can talk about what grown-ups do, like civilized people.”

Kasuka punches him. 

Izaya dodges, slicing through Kasuka’s fine black shirt with his knife, but Kasuka uses a trick he learned from a martial arts film to grip Izaya’s arm hard and make him drop the blade. 

He intends to use the grip to walk Izaya into the bedroom and lock him in until the car arrives, but he sees a large open box behind the couch first. 

He will only need to go as far as that box to collect the implements of revenge.

***

Shizuo blacks out a little. When he comes to, his vision has cleared but he’s still unable to move or speak. He’s on the couch under a blanket. Izaya is tied to a chair and Kasuka is unloading goods from their…sex toy box.

He remembers the shock of seeing Kasuka before he passed out, and from the look of things, his brother’s knocked around Izaya pretty bad. He can’t figure out what the hell is going on. 

“Ooh, are you going to get your revenge on me, Kasuka? You forget all those are mine. It’s not exactly torture. Some of them even belong to your brother. He bought them with that pathetic salary he used to have.”

“Before you locked him up here,” Kasuka replies. 

“This is where Shizu-chan and I live our lovey-dovey life,” Izaya coos.

The deadpan man doesn’t reply. He keeps unloading objects.

“Ah, nostalgic,” Izaya comments.

Shizuo agrees. He swears he hasn’t seen some of them in years. In Kasuka’s hand now is the purple crystal dildo some yakuza asshole gifted Izaya. He remembers the information broker opening the stupid gift-wrapped box that it came in and laughing his head off. 

Kasuka’s long fingers loop through the ring of their favorite anal beads. Then there’s a whole carton of Tenga eggs and Shizuo doesn’t even want to explain. That would mean getting into why he had to throw away so many masturbation sleeves that were torn to shreds before he could even finish in them. 

There are way too many condoms, particularly given their general disinterest in wearing them. There’s just enough toy wipes for Izaya to not complain about Shizuo washing stuff off with a dishrag. 

By the time Kasuka’s emptied the box, he’s encircled in a satanic sea of sexual devices. Shizuo is lost in memories and increasingly uncomfortable with his brother’s intrusion into his sex life. 

It gets worse, of course. 

Kasuka replaces the ropes on Izaya with thick leather shackles. They’re still fitted to Izaya – Shizuo remembers quite clearly how the flea hid them under his fur coat until they reached a spot just to the side of a main road. The metal loop clanged viciously against the pole he chained himself to as Shizuo fucked him. Now they keep Izaya’s arms locked behind him as Kasuka bends him over his desk and applies a spreader bar between the informant’s ankles. _Good idea_ , Shizuo thinks, incongruously. _He kicks._

“Hmmm, just like your brother?” Izaya smirks. “You want me too?”

“I would like you to understand the humiliation you’re putting my brother through,” Kasuka says. “And I would like to clear my brother of his delusions about you too.” He returns to the sex toy circle and searches for something.

“Oh, I know veeeery~ well about the first part. Would you like to hear? Anyway, Shizu-chan has no delusions about me, so perhaps you can end the charade here, Kasuka. Acting the role of the jealous brother is really unnecessary.”

Shizuo tries to move to stop things before they get worse. He can see a look on Kasuka’s serene face that he’s pretty sure he’s worn himself. Kasuka’s version is handsomer and subtler, of course. 

“I’m not acting or jealous. He deserves much better than a liar and criminal like yourself,” Kasuka selects a chrome-painted vibe, long and wide. Shizuo feels oddly possessive – that one’s his, the one that Izaya uses when he wants Shizuo to feel filled to bursting. 

Kasuka plunges the huge vibe between Izaya’s buttcheeks and deep inside. It’s a brutal thrust, swift and sure in a way that telegraphs the expressionless man’s quiet rage. Izaya actually yelps and cringes. Even his sex-slickened inner walls can’t handle an intrusion of that girth gracefully. 

“My apologies,” Izaya spits out. “I never knew the Heiwajima brothers were both animals. Your brother’s the gorilla but you’re a chimpanzee. Good with tools, ne?”

Kasuka looks around for tape, finds a roll of clever “caution” duct tape and slaps it across Izaya’s ass. That giant vibe isn’t going anywhere. 

“Take it out or I’m going to bleed,” Izaya grits between his teeth.

“My brother must have felt that way when you tied him up,” Kasuka says.

Shizuo doesn’t like this. He doesn’t like watching his brother being so cruel. He doesn’t like not being able to help Izaya. He wants the drugs to wear off quicker so he can put a stop to this.

Kasuka silently but firmly increases the intensity of Izaya’s torture. He slips a vibrating ring on his half-hard cock. Nipple clamps (ok – Shizuo did not know they owned those) go on the flea’s sensitive nubs. The setting on the vibe goes higher.

Izaya’s a shivering, whining wreck. Shizuo knows his pride must be hurting even worse than his abused body. Kasuka might be family, but only Ikebukuro’s strongest is allowed to see the information broker’s vulnerabilities. 

Izaya’s panting and thrusting into the air now, his cock straining for release. Kasuka removes the cock ring and replaces it with the soft silicon of a Tenga egg. The clear stretchy sleeve covers the length of Izaya’s cock as Kasuka grasps and strokes him. The information broker moans in pleasure, his red face lolling on the desk.

The way Kasuka’s stroking is all wrong. The rhythm doesn’t match what’s in Shizuo’s head. That’s not how Izaya is supposed to be touched. Kasuka’s hand is in the wrong place, twisting the wrong way and it pisses off Shizuo. Izaya isn’t turned off though – despite the improper touch he starts to break down. 

“Shizu-chan…” he calls. His bleary eyes fix on his lover. He moans loudly and lewdly as tremors overtake his body. The sweet, familiar sounds of Izaya’s climax make Shizuo’s ears burn with arousal. Kasuka pulls the egg away, its cache of semen splattering on the floor. 

Now Shizuo’s hard and knows Kasuka isn’t even close to done. 

“Ssstop….” Shizuo forces out.

Kasuka stops immediately. He comes over, kneels next to Shizuo and shakes his head. 

“Orihara can’t help you be the person you want to be. He only encourages the worst in you.”

The words hurt. They’re too direct, and his brother is usually so tactful. Maybe Kasuka’s tired of using subtlety on an idiot. 

“Nnn…” Shizuo grunts out.

“Your relationship with Orihara isn’t helping you master your violence. And having sex with him isn’t a substitution for living life.”

Shizuo’s eyes flutter open wide. “I’m…not….” But he can’t finish. Kasuka’s right – despite resisting for so long, lately he’s taken shelter in this sex vacation that being with Izaya can offer him.

Kasuka returns to the man in question, whose knees have buckled, ripping off the tape so the silver vibe spills out of the informant’s ass. It’s shiny with lube, Shizuo’s semen from before, and blood. Izaya slumps to the ground and rolls to his back with a whimper.

Kasuka reaches to insert another toy, the pink bunny dildo with rotating beads that “Kanra” uses. Before he can grind the thing into Izaya’s abused hole and dig the clit bunny into his balls, the information broker springs into action. His hips swivel and he knocks Kasuka off his feet.

All that parkour has made his core strong—Shizuo knows not to underestimate the flea’s flexibility and strength, but Kasuka doesn’t and finds himself quickly pinned to the floor. It seems Izaya had been waiting to be turned on his back before resisting, in order to maximize his chances of success. They tussle, but Izaya doesn’t lose position.

“I think that’s enough playing for today,” Izaya says. He’s using his legs to trap Kasuka’s hands and his body to pin him. “It wouldn’t be in my interest to hurt Shizu-chan’s little brother. It would make him awfully mad, and you see, and even though I think that would be incredibly amusing it would make things awkward between us now.” 

“My brother deserves to live his life.”

“You’re right, I’m selfish. By keeping Shizu-chan here, I am preventing him from being his best. He hasn’t destroyed a single building in the past few weeks. What a waste of his true potential, don’t you think?”

“You’re the only one who wants him to be that way, Orihara.”

“If it’s just a matter of taking my pet dog on a few walks, I can certainly do that to appease his little brother. Shall I have him wear a collar?” Izaya laughs.

Shizuo can finally move a little, and it’s time to put an end to this toxic scene. He reaches down and yanks Izaya’s hair. He’s not close to full strength, but even a fraction of his strength is forceful. 

“Oww, Shizu-chan!”

“Big brother,” Kasuka says. 

Shizuo gingerly sits up, pulling Izaya up by the hair. He tosses the flailing flea to the couch, then pulls Kasuka up by the arm. The movements make him dizzy, so he rests just a little. 

“Yer right…Kasuka,” he says. “Been hiding. Sorry…not returning your…calls.”

“That’s okay,” Kasuka says. 

“No listen…. You’re right but… I like the stupid flea.”

He turns to Izaya to undo the bondage. There’s a strange look on the information broker’s face that Shizuo watches intently as he fumbles with the handcuffs. Once he gets them open, Izaya swiftly removes the spreader bars. 

The three are at a standstill. 

Shizuo turns to Kasuka first. “It wasn’t nice what you did…but I forgive you because you’re my brother.”

“So you’re not wanted here anymore, goodbye,” Izaya adds.

“Shut up, flea.” Shizuo twists his arm. “You’re a little shit.”

Shizuo stands up and hugs Kasuka. It’s weird as hell because he’s still kinda hard and the blanket around his waist doesn’t conceal his erection well. 

But Kasuka understands. It seems Shizuo has said words that appease him. 

“I trust you.” He hugs Shizuo and then gives him the forgotten bottle of milk. Shizuo gulps the whole thing down. Kasuka watches until a notification on his smartwatch distracts him.

“My car is here. I’ll call you later about dinner on Sunday with Miss Ruri and I.”

“Don’t forget to invite me~ I’d love to tell stories about the fun time we just had.”

They both ignore Izaya. “Sounds good,” Shizuo says. They hug again before Kasuka closes the door behind him.

Shizuo sighs and collapses onto the couch. This whole thing was…a lot. The drugs still course through his system, slowing him. He leans back and pulls Izaya on top of him, where he can hold him and feel his weight. Izaya nuzzles against him, trembling. He’s not in much better shape. As much as he pretends not to have such emotions, all the fear and shame from earlier are catching up to him.

Shizuo’s overcome with a feeling of gratitude that he can be here for his lover like this. He strokes the silky black hair and his hands wander with affirming touches. It’s as Kasuka feared, really. He’s under the spell of this man. 

Izaya chuckles and rubs his hips against Shizuo’s. “Seeing me get fucked by your brother turned you on, Shizu-chan? Such a pervert.”

“Shut up. I was already hard,” It’s a half-lie.

That’s the end of the banter. Izaya sneaks his hand down Shizuo’s body and rubs his cock. 

“Shizu-chan wants to feel good,” Izaya teases. “But he can’t be inside me, I’m all tore open.”

“That’s not sexy, flea.”

“You’re nothing but sexy, Shizuo. You make me think of sex all the time. Even when your brother’s fucking me, all I can think of is you.”

“Shut up,” the reprimand is softer. 

“It’s true, that's how much I want you. I want you to feel so good, Shizu-chan.”

He does feel good, just having Izaya against him like this. He feels even better when the flea pumps his cock with delicious, firm strokes. The flea’s other hand occupies itself with the side of Shizuo’s face, caressing it and threading his fingers into the hair around his ear. 

Being with Izaya is so good. It’s sinful. It’s twisted and fucked up, but it’s this too: sweet and simple and full of passion. 

Shizuo’s hips thrust as orgasm builds. His cock buzzes with pleasure and Izaya’s warm against him and he comes into expectant hands. 

“Shizu-chan’s so messy,” Izaya laughs, pulling his white-stained hands up and shoving them in his lover’s face. Shizuo licks the juice off his fingers. He doesn’t mind the taste his own seed, it’s vaguely sweet. 

Izaya smiles and sighs, head flopping onto Shizuo’s chest like a dead weight. He traces circles on his lover’s arm. Shizuo flops the arm around him and holds him tight. Izaya squeezes back. It’s an affirmation that Izaya then takes one step further.

“Hey, Shizu-chan. Let’s go out for dinner.”

“Sounds good, flea.”

**Author's Note:**

> A shortish PWP – I just liked the idea of Kasuka not really understanding Shizuo and Izaya's relationship, and jumping to conclusions because Izaya is a bad person. And I like Shizuo being voluntarily drugged, always :)


End file.
